Apparatus such as facsimile, printer and electrophotographic copying machine require a paper feed roll for conveying paper. The conventional paper feed rolls are made of a synthetic rubber such as EPDM, urethane and polynorbornene. However, the paper feed rolls made of such a synthetic rubber leave something to be desired in fuser oil resistance, light resistance and heat resistance.
In order to eliminate these disadvantages, various studies have been made. For example, a hardened silicone rubber composition comprising organopolysiloxane containing vinyl groups, resinous organopolysiloxane containing vinyl groups, organohydrogen polysiloxane, platinum or platinum compound and antistatic properties donor (see JP-A-60-130648 (The term "JP-A" as used herein means an "unexamined published Japanese patent application")), a silicone rubber roll made of an amorphous silicone rubber powder obtained by grinding silicone rubber (refer to JP-A-1-159239), an automatic paper feed rubber roller blended with diphenylsilane diol (refer to JP-A-4-298426), a paper feed rubber member obtained by the formation of a silicone rubber having a tear strength of not more than 15 kgf/cm (refer to JP-A-5-116778), etc. have been proposed.
If synthetic rubbers other than silicone rubber are used to prepare a paper feed roll, a problem arises that when a silicone oil is used for the purpose of releasing toner, the silicone oil gradually migrates to and accumulates on the rubber roll to cause a remarkable drop of friction coefficient. In order to solve the foregoing problem, a silicone rubber composition for use in the paper feed roll adapted for silicone oil as disclosed in the above cited patents has been proposed. However, such a silicone rubber composition cannot provide a high friction coefficient or is liable to a great wear after a prolonged operation of paper feed that causes a change in friction coefficient. Thus, there have been no satisfactory rolls.